As COVID-19 vaccine development pushes ahead, researchers probe safety

Researchers developing COVID-19 vaccinations say they are taking steps to ensure sure their vaccine candidates attack the disease rather cause infection. Upcoming final-stage trials will look for signs of rare adverse effects that emerged during the development of vaccines for dengue and other types of coronaviruses.

Researchers developing COVID-19 vaccinations say they are taking steps to ensure sure their vaccine candidates attack the disease rather cause infection. Upcoming final-stage trials will look for signs of rare adverse effects that emerged during the development of vaccines for dengue and other types of coronaviruses. Moderna, Pfizer, and other companies report their vaccine candidates have demonstrated to be generally safe and well-tolerated in early testing in small groups of people. Johnson & Johnson is developing a vaccine targeting the novel coronavirus' spike protein and expects to start human testing in July. The aim is to create high levels of neutralizing antibodies and T-cells. In small, early-stage studies, some COVID-19 vaccine subjects experienced short-lived fevers or sore arms after vaccinations, according to drug companies. Moderna chief medical officer Tal Zaks says certain reactions, such as fatigue, can indicate that the vaccine triggered the desired immune response.